Method and apparatus for extracting zinc.



E. S. BERGLUND.

METHOD AND APPARATUS FOR EXTRACTING ZINC.

APPLICATION FILED FEB. I5, 1916.

Patented Aug. 14, 1917.

E5. Berg/Una.

Ira water" fur 1 EDWARD SALOMON BERGLUND, F TROLLHATTAN, SWEDEN. METHODAND APPARATUS FOR. EXTRACTING- ZINC.

masses.

Application filed February 15, 1916. Serial No.

To all whom it may concern:

Be it known that I, EDWARD SALOMON BERGLUND, engineer, a subject of theKing of Sweden, residing at Trollhattan, Sweden, have invented new and.useful Improvements in the Method and Apparatus for Extracting Zinc, ofwhich the following is a specificat1on.

When condensing zinc vapors, generated in an electric furnace, adaptedfor the extraction of zinc from its ores, part of the zinc isobtained ina condition of powder, so called poussz're, and not in liquid condition,especially in that part of the condenser,

WhlCll is most remote from the escape open- J ing of the furnace.

This fact is dependent on many circumstances, among others thereof, thatthe zinc vapors as a rule are diluted with other gases or vapors; andthat it is difficult to maintain the different temperatures, which aremost suitable for the condensation of differently diluted zinc vapors,in different parts of the condenser.

If the temperature is maintained so high throughout the condenser, thatzinc is condensed in a liquid condition in said, remote parts of thecondenser, the whole amount of zinc will not be condensed in thecondenser, as the temperature then will betoo high for condensing thevapors in such parts of the condenser, which are nearer to the electricfurnace, the result being that a considerable part of the zinc vaporsescape together with the other gases from the condenser, which zincvapors thus are lost if special arrange ments are not provided.

When withdrawing the p oussire, usually generated in the condenser, saidpoussz're is oxidized byith'e air and will burn to 'oxidd which must bereduced to zinc by a secon treatment in the electric furnace. 1

This means a considerable inconvenience, partly because carbon isconsumed for the reduction, and partly because gases are developed,which dilute the zinc vapors and make the condensation diflicul v Thepresent invention refers to a method adapted to avoid saidinconveniences and consists therem, that the poussire generated in thecondenser, is introduced directly in a furnace, without getting theopportunity of coming in contact with the air.

Figure 1 shows a plan of an electric furnace in combination withcondensing arrangements according to the present inven- Specification ofLetters Patent.

paratively high,

makes the ordinary Patented Aug. Ml, 1191?. 78,381.

tion. Fig. 2 is a vertical section on line A-B in Fig. 1. Fig. 3 is avertical section on line C-D in Fig. 1, and Figs. 4 and 5 are verticalsections on lines E-F and G-H respectively in Fig. 1.

1 indicates an electric furnace, to which is jointed a condenser 2, inwhich by means of the brick lining 3 or .by other suitable means thetemperature is maintained comsuch temperature being adusted in such amanner, that mainly liquid zinc is obtained by condensation, and only asmall quantity of poussz're. The condenser 2 is'divided by means of oneor more partition walls 4 in two or more partitions, through which thegases pass in the manner indicated by the arrows in Figs. 2 and 4.

To said condenser is joined a second condenser 5, in which thenon-condensed gases, escaping from the condenser 2, are cooled in such amanner, that practically all zinc contained in such gases is condensedin'the form of powder or poussz're. For this purpose the condenser 5 ismade of sheet iron without'any lining of insulating material, and isprovided with a number of pipes 6 or the like, in order to augment thecondensing surface. The condenser 5 may also consist of a pipe system ofcast iron or the like. From said condenser 5 the remaining gases whichdo not contain zinc and which cannot be condensed, are withdrawn throughthe outlet 7 In the arrangement illustrated on the drawings thecondenser 5 is connected with the furnace l by means of a channel 8,which is provided with a screw conveyer 9 or similar device, adapted tofeed the zinc powder (poussz're), generated in the condenser 5, intosaid furnace This poussz're thus charge, contained in the furnace,considerably richer in zinc, whereby the escaping gases also will bericher in zinc and easier to condense to a liquid condition than whenthe ordinary alone is treated in the furnace.

f desired the whole or part of the ordinary ore charge may be introducedinto the condenser 5 through a suitable feed opening 10, whereby suchcharge will be preheated in the condenser 5, and said lattersimultaneously will be correspondingly cooled. In such case the chargeas well as the poussz're is introduced in the furnace l by means of thescrew conveyer 9.

By means of the method now described the poussz're generated isprevented from ore charge described in the furnace, part of the zincextracted in said furnace is circulated through the furnace andcondenser system in a closed cycle, whereby the gases escaping from thefurnace, after a certain condition of continuity has entered, willreceive their greatest concentration, which is attainable under theexisting circumstances, so that the condensation will be highlyfacilitated. If said convenience is dispensed with the channel 8 withthe screw conveyer 9 may open into another furnace than the furnace 1,in which the poussz're is treated for extracting the zinc, containedtherein. The condenser, in which the gases are introduced from thefurnace 1 according to the present invention, consists of two differentcompartments 2 and 5. The compartment 2, through which the gases firstpass, is constructed and arranged in such a manner, that a comparativelyhigh temperature is maintained therein so that zinc is condensed in aliquid condition. The compartment 5 on the contrary is constructed sothat the gases entering the same from the first compartmentare cooled insuch a degree, that practically all zinc is condensed therein in apulverous condition.

The convenience is obtained hereby, that mainly liquid zinc is condensedin the first compartment, which zinc is drawn off,

whereas only a small quantity of poussre is generated. In thesecond-compartment 5 the Z1110 is condensed exclusively in condition ofpowder or posssire, which is or may be re-introduced by means of thescrew conveyer 9 to the furnace 1.

What I claim as my invention and desire to secure by Letters Patent is:

1. In the electro-thermic extraction of zinc, condensing the zincvapors, precluding contact between air and the zinc powder" formed andre-introducing thezinc powder into the furnace and thereby increasingthe content of zinc in the furnace gases.

' tracted in a closed cycle 2. In the electro-thermic extraction of zinccondensing the furnace gases in two successive steps and re-introducingthe zinc powder, formed by the second condensing step into the furnace,precluding its contact with air, so that part of the zinc extracted iscirculated through the furnace and condenser system in a closed cycle.

3. In the electro-thermic extraction of zinc increasing the content ofzinc in the furnace gases by circulating part of the zinc exthrough thefurnace and condenser system.

4. A zinc condenser, comprising two compartments in succession, one ofsaid compartments connected with the escape opening of an electricfurnace and lined with heat insulating material, and the secondcompartment connected with an inlet of said electric furnace and withoutsuch insulating lining.

5. A zinc condenser comprising two compartments in succession, one ofsaid com- .ipartments being connected with the escape opening of anelectric furnace and the second compartment being connected with aninlet to the said electric furnace.

6. A zinc condenser, comprising two compartments in succession, one ofsaid compartments connected with the escape opening of an electricfurnace, and the second compartment provided with means for introducingpowder, contained therein, into an electric furnace.

7. A zinc condenser, comprising two condensing compartments insuccession, one of said compartments connected with the escape openingof an electric furnace, and the second compartment provided with meansfor introducing a zinc containing charge in said compartment, and withmeans for introducing said charge from said compartment into an electricfurnace.

In testimony whereof I have signed my name to this specification in thepresence of two-subscribing witnesses.

' EDWARD SALOMON BERGLUND- Witnesses:

HUGO IJINDBRAU, BCMH. ONSCER.

